US20040106942A1 - Universal access seal - Google Patents

Abstract

A surgical access device including a valve housing and an instrument receiving element mounted in the valve housing having an aperture for flexibly receiving and directing instruments having a wide range of diameters. The instrument receiving element includes a braid or mesh tube generally shaped like an hourglass. The surgical access device may include an access septum seal molded from a gel material. The surgical access device can flexibly engage instruments having diameters ranging from about 3.5 mm to about 12.9 mm.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention[0001]
• The present invention generally relates to surgical access devices and, more particularly, to an access seal providing passage of instrumentation and for maintaining pneumoperitoneum during laparoscopic surgeries.[0002]
• 2. Description of Related Art[0003]
• Surgical access devices, such as a[0004]trocar10 illustrated in FIG. 1, typically include acannula2 and a valve housing4 that define a working channel6 across a body wall7, such as an abdominal wall, and into abody cavity8, such as an abdominal cavity. The cannula is typically formed as an elongate rigid cylinder that is inserted, with the help of an obturator, into the body cavity to provide access across the body wall.
• In a typical abdominal laparoscopic surgery, the abdomen is insufflated to pressurize and thereby enlarge the cavity within which a surgical procedure is to be performed. Various instruments used in the procedure are inserted, previously one at a time, through the working channel of the trocar to perform the surgery. In order to maintain the insufflation pressure when the instrument is inserted through the trocar, a valve has been provided in the housing to form a seal around the instrument. These instrument valves have typically been provided in the form of septum valves. When the instrument is removed, a zero-closure valve has typically been provided to seal the trocar in order to maintain the insufflation pressure. A zero-closure valve such as a double duckbill valve disclosed in U.S. Pat. No. 6,162,196, which is incorporated herein by reference, may be used.[0005]
• Surgical instruments, however, vary in size and diameter. While the zero-closure valves can accommodate a relatively wide range of diameters, the septum valves are generally capable of stretching only a nominal amount to accommodate larger diameters. Specifically, the septum valves are generally formed in valve sets that are limited to the range of instruments that they can accommodate. When an instrument was required that had a diameter outside the range of a valve set, the entire trocar or at least the housing supporting the valve set had to be replaced with one that could accommodate the new instrument. In some cases, septum valves having universal seals were provided to accommodate different ranges of instrument diameters. These universal seals were typically made of elastic and tearable materials that often tear or puncture causing loss of insufflation gases. Attempts have also been made to include multiple septum seals to accommodate instruments having various diameters. For example, a septum valve may include one septum seal to engage large diameter instruments and another septum seal to engage smaller diameter instruments. These septum valves with multiple septum seals are typically more expensive to manufacture. Moreover, the seals are still limited to the specific range of instruments they can support.[0006]
• Accordingly, there is a need in the art for a universal access seal capable of accommodating a wide range of instrument sizes. In particular, the universal access seal should be able to sealingly engage instruments of various diameters ranging from about 3.5 mm to about 12.9 mm. An access seal covering this range of instruments would reduce adjustments and, thus, time and costs required during surgery. It is also desirable for the universal access seal to perform when a sharp instrument is inserted off-center or when an instrument is moved radially after insertion. It is further desirable that the universal access seal facilitates the insertion and removal of instruments including tissue removal.[0007]
SUMMARY OF THE INVENTION
• A surgical access device including a universal access seal is capable of accommodating instruments of various diameters. The universal access seal comprises a braid or mesh tube that is preferably shaped like an hourglass. The universal access seal can sealingly engage instruments of various diameters ranging from about 3.5 mm to about 12.9 mm. The braid facilitates insertion and manipulation of surgical instruments by directing the instruments along an axis of the surgical access device. In another embodiment of the invention, the surgical access device further includes a septum seal that is preferably molded from a gel material. The gel septum seal further facilitates the insertion and removal of instruments. These and other features and advantages of the invention will become more apparent with the description of preferred embodiments and reference to the associated drawings.[0008]
DESCRIPTION OF THE DRAWINGS
• FIG. 1 illustrates a common surgical access device such as a trocar of the prior art;[0009]
• FIG. 2 illustrates a surgical access device in accordance with a first embodiment of the invention;[0010]
• FIG. 3 is an axial cross-section view taken along line A-A of FIG. 2;[0011]
• FIG. 4 illustrates a surgical access device in accordance with a second embodiment of the invention;[0012]
• FIG. 5 illustrates a valve housing of the surgical access device of the invention;[0013]
• FIG. 6 is an axial cross-section view taken along line B-B of FIG. 5;[0014]
• FIG. 7 illustrates a valve septum seal of a surgical access device in accordance with another embodiment of the invention;[0015]
• FIG. 8 is an axial cross-section view taken along line C-C of FIG. 7;[0016]
• FIG. 9 illustrates a valve septum seal of a surgical access device in accordance with another embodiment of the invention; and[0017]
• FIG. 10 is an axial cross-section view taken along line D-D of FIG. 9.[0018]
DESCRIPTION OF PREFERRED EMBODIMENTS
• The following detailed description refers to the accompanying drawings that illustrate the embodiments of the present invention. Other embodiments are possible and modifications may be made to the embodiments without departing from the spirit and scope of the invention. Thus, the following detailed description is not meant to limit the invention. Rather the scope of the invention is defined by the appended claims.[0019]
• Referring to FIGS. 2 and 3, there is shown a first embodiment of a[0020]trocar10 including acannula12 and avalve housing14. Cannula12 defines an interior lumen having an opendistal end portion16 and an openproximal end portion18.Proximal end portion18 extends into and is mounted in adistal end portion20 ofvalve housing14. Valvehousing14 has an openproximal end portion22 that defines anopening24. An obturator can be inserted intovalve housing14 andcannula12 through opening24 as further described below.
• Valve[0021]housing14 includes anaccess port26, which comprises a braid ormesh tube38 having an aperture orcentral sealing orifice39 adapted to receive a wide range of instrument sizes.Access port26 further includes anend cap28 for mountingbraid38.End cap28 is typically disposed in a radial plane generally perpendicular to atrocar axis30.Braid38 includesbraid elements38band is preferably made of polyester, which provides a low-friction, expandable lead-in toaperture39. Braid38 can sealingly engage instruments inserted therethrough having diameters ranging from about 3.5 mm to about 12.9 mm. As an instrument such as an obturator is inserted intoaccess port26,braid38 expands to the size of the instrument so that it forms a tight seal with the outer surface of the instrument and directs the instrument throughaperture39. By directing the instrument throughaperture39,braid38 minimizes the possibility of tearing even if the instrument is inserted off-center or off-axis.
• [0022]Braid38 is generally shaped like an hourglass having converging and divergingsidewalls42aand42b, respectively, that facilitate the insertion and removal of instruments throughaccess port26.Braid38 can be made from a variety of natural and synthetic monofilament thread materials including polyester, Kevlar, carbon fiber, Gore-Tex (expanded PTFE), Nomex, nylon, fiber glass, cotton, polypropylene and ceramic. Braidelements38b, which are preferably woven from a polyester monofilament having a diameter of about 0.005″, may stretch, flex, slide and/or expand in response to the direction and movement of the inserted instrument. Braidelements38b can be made from various metal wire materials including music wire, stainless steel and Nitinol. These materials allow greater interstitial spacings withinbraid elements38bthat result in less contact between the inserted instrument and braid38 to produce a more effective seal between an elastomer and the instrument as further described below.
• [0023]Braid38 can be permanently coated or treated with a variety of materials and/or processes designed to reduce friction between inserted instruments andbraid38. The coatings may be applied on eachindividual braid element38bor as layers over the braid elements. The layers may be external, internal or may encapsulatebraid38. The friction reducing materials include any soft or low-durometer elastomeric material. The elastomeric material could be at least one of a thermoplastic and a thermoset. Examples of the elastomeric materials include silicone, polyurethane, polyisoprene and Kraton. Examples of other coatings and treatments include hydrophilic polymer coatings, Teflon (PTFE) coatings, cyanoacrylate coatings, Parylene coatings, plasma surface treatments and chlorination treatments.
• In a second embodiment of the invention as illustrated in FIG. 4,[0024]access port26 further includes aseptum seal36 having anaperture40.Aperture40 measures about 0.115″ in diameter and is in line withtrocar axis30.Braid38 is configured toline aperture40 ofseptum seal36.Septum seal36 may also stretch, flex, swivel and/or slide to receive the inserted instrument.Septum seal36 may be configured to float withinvalve housing14 to minimize the cat-eye effect around the inserted instrument, which can result in seal leakage during manipulation of the instrument. In another embodiment of the invention,valve housing14 further includesfinger tabs11aand11bproviding means for engagingtrocar10 and manipulatingcannula12 into a preferred operative position. In another embodiment of the invention,access port26 is configured as a hand-access port to allow passage of a surgeon's hand or finger into the peritoneal cavity of a patient. In another embodiment of the invention,access port26 is utilized as a hemostasis valve for vascular or cardiovascular surgeries to prevent loss of blood yet allows passage of guidewires, catheters and other devices into the arterial or venous system of a patient. In yet another embodiment of the invention,access port26 is utilized as an endoscopic valve for urological procedures to prevent loss of fluids yet allows passage of guidewires, catheters and other devices into the urethra or ureter.
• [0025]Septum seal36 is preferably molded from a gel material and is preferably encased in a seal housing to affect a radial compressive force about the outside diameter ofseptum seal36. As an instrument is inserted intobraid38,braid38 expands whileseptum seal36 resists expansion due to the outer compressive force provided by the seal housing. This forces the gel material to extrude throughinterstitial spaces38ato sealingly engage the outside diameter of any instrument inserted throughaccess port26 while minimizing the frictional contact between the inserted instrument andseptum seal36. The gel material has a low durometer that enables it to extrude throughinterstitial spaces38a. The gel material is preferably a composite material comprising mineral oil and a thermoplastic elastomer such as a Kraton material.
• [0026]Septum seal36 could also be manufactured from a closed cell foam material or an open cell foam material sealed with a film coating. Examples of the foamed materials include silicone, urethane, Kraton, polyethylene, polyisoprene, polyvinylchloride (PVC), polyurethane, ethylene propylene diene monomer (EPDM), Neoprene and styrene butadiene (SBR).Septum seal36 may be coated or treated with a variety of materials and/or processes designed to reduce friction between the inserted instruments and the gel material. Examples include hydrophilic polymer coatings, Teflon (PTFE) coatings, thermoplastic coatings, cyanoacrylate coatings, Parylene coatings, plasma surface treatments, cornstarch powder coatings and chlorination treatments.Septum seal36 may also be lubricated with a variety of materials to facilitate the insertion and withdrawal of instruments. Examples of these materials include silicone oil, silicone grease, liquid soaps, Astroglide lubricants, mineral oil, glycerin, alcohol, saline, Teflon (PTFE) lubricants, Krytox lubricants, molybdenum disulfide lubricants and graphite.
• Another aspect of the invention is[0027]braid elements38balso serve to reduce the force required to insert and advance an instrument throughseptum seal36. The coefficient of kinetic friction (f) forpolyester braid38/septum seal36 verses a metal or polymer instrument shaft is significantly less than that of an elastomeric septum seal verses a metal or polymer instrument shaft. Typical coefficient of kinetic friction values range from about 0.15 to about 0.5 for polymers such as polyester verses steel, whereas the typical coefficient of kinetic friction values for elastomers verses steel range from about 1.6 to about 10. As a result,braid elements38bminimize the contact between the shaft of the inserted instrument andseptum seal36 and minimize the frictional forces required to insert and advance the instrument throughseptum seal36.
• Braid[0028]elements38balso serve to capture lubricants such as oils and greases withininterstitial spaces38a. In particular,interstitial spaces38acapture lubricants to prevent inserting instruments from wiping all of the lubricants frombraid38 andseptum seal36 during instrument exchanges. That is, some lubricant will always be present withinbraid elements38bto facilitate manipulation and exchange of instruments throughout the surgical procedure. The presence of lubricants also improves the sealing properties of the present invention. As observed with prior art trocar seals, lubricants such as oils and greases are typically completely transferred from the lubricated septum seals to the inserted instruments after a few instrument exchanges resulting in a non-lubricated septum seal for the remainder of the surgical procedure. A drawback of the prior art seals is subsequent instrument manipulations and exchanges become increasingly difficult for the operating surgeon or user.
• With the flexibility of the braid and septum seal of the invention, an instrument having a sharp, irregular, forked or otherwise potentially damaging distal features may be directed through the access port in a minimally threatening position. The braid, either alone or in combination with the septum seal, can stretch, flex, slide and/or expand so as to easily receive an approaching instrument. The flexibility of the braid and septum seal thus provides a very durable and relatively friction-free insertion and removal of instrumentation.[0029]
• [0030]Access port26 may further comprise a zero-closure valve34 such as a double duckbill valve, which maintains pneumoperitoneum in the absence of inserted instrumentation as described in the incorporated U.S. Pat. No. 6,162,196. With this embodiment,valve housing14 andcannula12 extend alongtrocar axis30 and define a workingchannel32 for receipt of a surgical instrument. In the absence of an instrument, zero-closure valve34 closes on itself forming a gas-tight seal at very low retrograde pressure and preventing loss of insufflation gas. When an instrument is present in workingchannel32,braid38 and/orseptum seal36 forms a seal with the instrument in order to seal workingchannel32. In particular,access port26 provides a positive seal with respect to instruments inserted therethrough.
• [0031]Access port26 may further comprise a manifold46 and a stopcock48, both of which are preferably molded from polycarbonate.Manifold46 is positioned withinvalve housing14 and serves to locate zero-closure valve34 andseptum seal36 relative tovalve housing14.Manifold46 also facilitates the flow of insufflation gasses from an insufflator, throughcannula12 and into the surgical site.End cap28 is preferably ultrasonically welded tovalve housing14 and serves to fixmanifold46, zero-closure valve34,septum seal36 andbraid38 withinvalve housing14. The proximal end ofbraid38 is preferably bonded to endcap28 and the distal end ofbraid38 is not attached to any component and is free to float withinaccess port26.Braid38 is preferably flared at both the proximal end and the distal end in an hourglass shape. In another embodiment of the invention, the proximal end ofbraid38 is bonded or fixed tomanifold46 to prevent migration during instrument insertion and removal. Zero-closure valve34 is preferably molded from polyisoprene and is located distal toseptum seal36. As illustrated in FIGS. 5 and 6,valve housing14 includingaccess port26 may be removably attached to a disposable orreusable cannula12.
• The following describes the preferred method of manufacturing an access port in accordance with an embodiment of the invention. Zero-[0032]closure valve34, which is preferably transfer molded, is first placed intovalve housing14, which is preferably injection molded.Manifold46, which is preferably injection molded, is then mounted on top of zero-closure valve34.Septum seal36, which is preferably injection molded, is then placed on top ofmanifold46.Braid38, which is preferably heat set to form flared sections at its proximal and distal ends, is then bonded to endcap28, which is preferably injection molded. The distal end ofbraid38 is then threaded throughaperture40 ofseptum seal36, andend cap28 is positioned on top ofvalve housing14 to effectively capture all of the access port components.End cap28 is then ultrasonically welded tovalve housing14.Stopcock48 is then bonded tovalve housing14. The housing assembly is then removably attached, via bayonet locks, to cannula12, which is preferably injection molded from polycarbonate.
• In another embodiment of the invention, FIGS. 7 and 8 illustrate a[0033]septum seal60 comprising a plurality of coredsections60a-60dspaced about acentral aperture62 that enableseptum seal60 to deform in response to insertion of an instrument.Cored sections60a-60dmay be formed in either or both of the top and bottom surfaces ofseptum seal60 as illustrated in cross-section view C-C in FIG. 8. In yet another embodiment of the invention, FIGS. 9 and 10 illustrate aseptum seal80 comprising a plurality ofsmall apertures82aand82bconnected topockets88aand88b, respectively.Small apertures82aand82bare in fluid communication with and are oriented perpendicular toinstrument insertion aperture86.Pockets88aand88bare located withinseptum seal80 and serve to store lubricants. When an instrument is inserted throughaperture86,septum seal80 deforms forcing the lubricants to ooze from storage pockets88aand88bthroughapertures82aand82b, respectively, thereby lubricating the instrument and facilitating its insertion and manipulation.
• It is appreciated that various fillers and additives could be incorporated into the various elastomeric septum seal materials to reduce the tackiness and to increase the lubricity of the material thereby facilitating the insertion and removal of instruments. Examples of the additives include waxes, soaps, paraffin wax, beeswax, calcium stearate, stearic acid, silicone oil, silicone grease, mineral oil, glycerin, graphite, silica, glass spheres, Teflon (PTFE), Parylene, talc and molybdenum disulfide.[0034]
• Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, it must be understood that the illustrated embodiments have been set forth only for the purposes of examples and that they should not be taken as limiting the invention.[0035]

Claims (50)

1. A surgical access device operatively connected to a cannula having an axis extending between a proximal end and a distal end, comprising:

a valve housing disposed at the proximal end of the cannula; and

an instrument receiving element mounted in the valve housing having an aperture for flexibly receiving and directing instruments having a wide range of diameters.

2. The surgical access device recited inclaim 1, further comprising an access septum seal disposed in the valve housing having a septum seal aperture.

3. The surgical access device recited inclaim 1, wherein the instrument receiving element includes a tubular braid.

4. The surgical access device recited inclaim 3, wherein the braid is coated with a material for reducing friction.

5. The surgical access device recited inclaim 4, wherein the coating includes any soft or low-durometer elastomeric material.

6. The surgical access device recited inclaim 5, wherein the elastomeric material includes at least one of a thermoplastic and a thermoset.

7. The surgical access device recited inclaim 5, wherein the elastomeric material includes at least one of silicone, polyurethane, polyisoprene and Kraton.

8. The surgical access device recited inclaim 4, wherein the coating includes at least one of hydrophilic polymer coating, Teflon (PTFE) coating, cyanoacrylate coating and Parylene coating.

9. The surgical access device recited inclaim 3, wherein the braid is treated with at least one of plasma surface treatment and chlorination treatment for reducing friction during passage of instrumentation.

10. The surgical access device recited inclaim 2, wherein the access septum seal may stretch, flex, swivel and/or slide in response to movement of an inserted instrument.

11. The surgical access device recited inclaim 2, wherein the access septum seal is configured to float within the valve housing to minimize the cat-eye effect around an inserted instrument.

12. The surgical access device recited inclaim 1, wherein the instrument receiving element includes a mesh tube.

13. The surgical access device recited inclaim 1, wherein the instrument receiving element is generally shaped like an hourglass.

14. The surgical access device recited inclaim 13, wherein the instrument receiving element includes a converging sidewall facilitating insertion of an instrument and a diverging sidewall facilitating removal of the instrument.

15. The surgical access device recited inclaim 1, wherein the range of diameters is from about 3.5 mm to about 12.9 mm.

16. The surgical access device recited inclaim 3, wherein the braid further comprises braid elements.

17. The surgical access device recited inclaim 3, wherein the braid comprises at least one of natural and synthetic monofilament thread materials including polyester, Kevlar, carbon fiber, Gore-Tex (expanded PTFE), Nomex, nylon, fiber glass, cotton, polypropylene and ceramic.

18. The surgical access device recited inclaim 16, wherein the braid elements comprise a metal wire material including music wire, stainless steel and Nitinol.

19. The surgical access device recited inclaim 16, wherein the braid elements provide interstitial spaces between an inserted instrument and the braid.

20. The surgical access device recited inclaim 4, wherein the coated braid expands to form a seal around an outer surface of an instrument.

21. The surgical access device recited inclaim 1, further comprising a zero-closure valve disposed in the valve housing.

22. The surgical access device recited inclaim 1, wherein the valve housing further comprises means for manipulating the cannula to a preferred operative position.

23. The surgical access device recited inclaim 22, wherein the manipulating means includes finger tabs.

24. The surgical access device recited inclaim 1, further comprising an end cap for mounting the instrument receiving element.

25. The surgical access device recited inclaim 1, wherein the valve housing is configured as a hand-access port allowing passage of a user's hand or finger into a body conduit or cavity.

26. The surgical access device recited inclaim 19, wherein the braid elements capture lubricants within the interstitial spaces to facilitate manipulation and exchange of instruments.

27. The surgical access device recited inclaim 2, wherein the access septum seal is molded from a gel material.

28. The surgical access device recited inclaim 27, wherein the gel material extrudes through interstitial spaces of the instrument receiving element sealingly engaging an instrument while minimizing frictional contact between the instrument and the access septum seal.

29. The surgical access device recited inclaim 27, wherein the gel material is a composite material comprising mineral oil and a thermoplastic elastomer.

30. The surgical access device recited inclaim 27, wherein the gel material comprises a soft or low-durometer elastomeric material that is at least one of a thermoplastic and a thermoset.

31. The surgical access device recited inclaim 30, wherein the elastomeric material includes at least one of silicone, polyurethane, polyisoprene and Kraton.

32. The surgical access device recited inclaim 27, wherein the gel material comprises a closed cell foam material or an open cell foam material.

33. The surgical access device recited inclaim 32, wherein the foam material includes at least one of silicone, urethane, Kraton, polyethylene, polyisoprene, polyvinylchloride (PVC), polyurethane, ethylene propylene diene monomer (EPDM), Neoprene and styrene butadiene (SBR).

34. The surgical access device recited inclaim 1, further comprising a manifold.

35. The surgical access device recited inclaim 1, further comprising a stopcock.

36. The surgical access device recited inclaim 2, wherein the access septum seal comprises cored sections spaced about the septum seal aperture enabling the access septum seal to deform during insertion and removal of an instrument.

37. The surgical access device recited inclaim 2, wherein the access septum seal comprises pockets storing lubricants and lubricant releasing apertures connecting the pockets to the septum seal aperture.

38. The surgical access device recited inclaim 37, wherein the lubricant releasing apertures are oriented perpendicular to the septum seal aperture.

39. The surgical access device recited inclaim 38, wherein the access septum seal deforms forcing the lubricants to ooze from the pockets through the lubricant releasing apertures thereby lubricating the instrument and facilitating instrument insertion and manipulation.

40. The surgical access device recited inclaim 2, wherein the access septum seal further includes additives including at least one of waxes, soaps, paraffin wax, beeswax, calcium stearate, stearic acid, silicone oil, silicone grease, mineral oil, glycerin, graphite, silica, glass spheres, Teflon (PTFE), Parylene, talc and molybdenum disulfide to reduce tackiness and increase lubricity.

41. A surgical access device for providing access across a body wall and into a body conduit or cavity, comprising:

a cannula having an axis extending between a proximal end and a distal end;

a valve housing disposed at the proximal end of the cannula; and

an instrument receiving means mounted in the valve housing having an aperture for flexibly receiving and directing instruments having a wide range of diameters.

42. The surgical access device recited inclaim 41, further comprising an access septum seal disposed in the valve housing having a septum seal aperture.

43. The surgical access device recited inclaim 41, wherein the cannula is either disposable or reusable.

44. The surgical access device recited inclaim 43, wherein the valve housing is removably attached to the disposable or reusable cannula.

45. The surgical access device recited inclaim 42, wherein the access septum seal is configured to float within a cavity of the valve housing.

46. The surgical access device recited inclaim 41, wherein the instrument receiving means includes a braid or a mesh tube generally shaped like an hourglass.

47. The surgical access device recited inclaim 42, wherein the access septum seal is molded from a gel material.

48. The surgical access device recited inclaim 41, wherein the instrument receiving means is coated with a friction reducing material.

49. A trocar for providing access into a body cavity, comprising:

a cannula defining a lumen having an open distal end portion and an open proximal end portion for accommodating a surgical instrument inserted therethrough;

a valve housing adjoining the proximal end portion of the cannula defining a housing having open distal and proximal end portions that communicate with the cannula lumen and permit insertion and removal of the surgical instrument therethrough; and

sealing means positioned in the valve housing, the sealing means defining a center bore portion allowing the surgical instrument to pass therethrough in sealing engagement therewith, the sealing means sealing the proximal end portion of the valve housing, and the sealing means having an hourglass shape defining converging and diverging sidewalls that form the center bore portion at the intersection thereof.

50. The trocar recited inclaim 49, wherein the sealing means comprises an expanding means for enlarging the center bore portion to increase the diameter thereof, the expanding means deflects the center bore portion in an axial direction.

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